Method and Apparatus for Reducing Downhole Losses in Drilling Operations, Sticking Prevention, and Hole Cleaning Enhancement

ABSTRACT

A downhole tool for use within a wellbore extending into an underground formation includes a wellbore wall disengaging assembly having a tubular string defining a longitudinal axis, and a plurality of longitudinal blades forming a retractable sleeve around the tubular string, the retractable sleeve having a substantially contiguous inner profile in a closed position, and wherein the retractable sleeve is actuated based on an internal pressure in the tubular string proximate to the downhole tool. A method of disengaging a downhole tool from a wall of a wellbore extending into an underground formation includes lowering a wellbore wall disengaging assembly, the assembly comprising a tubular string defining a longitudinal axis, and a plurality of longitudinal blades forming a retractable sleeve around the tubular string, the retractable sleeve having a substantially contiguous inner profile in a closed position, and actuating the retractable sleeve.

TECHNICAL FIELD

The present invention relates to drilling of wells for exploration or production of hydrocarbons. More specifically, the invention relates to systems and methods for disengaging a downhole tool from a wall of a wellbore extending into an underground formation, and reducing downhole losses in drilling operations.

BACKGROUND

Formation evaluation, whether during a wireline operation or while drilling, often requires that fluid from the formation be drawn into a downhole tool for testing and/or sampling. Various sampling devices, typically referred to as probes, are extended from the downhole tool to establish fluid communication with the formation surrounding the wellbore and to draw fluid into the downhole tool. A typical probe is a circular element extended from the downhole tool and positioned against the sidewall of the wellbore. A rubber packer at the end of the probe is used to create a seal with the wellbore sidewall. Another device used to form a seal with the wellbore sidewall is referred to as a dual packer. With a dual packer, two elastomeric rings expand radially about the tool to isolate a portion of the wellbore therebetween. The rings form a seal with the wellbore wall and permit fluid to be drawn into the isolated portion of the wellbore and into an inlet in the downhole tool.

In oil and gas operations, downhole tools (such as wire line tools or drill strings) are conveyed into and withdrawn from the wellbore. Occasionally, during operation, the downhole tool may become stuck in the wellbore. Tool sticking often occurs during formation evaluation procedures, such as coring or formation fluid sampling, where a piston and/or a probe are extended into contact with the mudcake lining the wellbore. Alternatively, a tool may also become stuck during delivery into or removal from the wellbore should it contact with and breach the integrity of the mudcake layer. The formation itself is typically at a relatively lower pressure, while the wellbore is at a relatively higher pressure. Consequently, it is possible for a downhole tool to dislodge a portion of the mudcake layer and expose the tool to a significant pressure differential that holds the tool against the wellbore wall. The holding force generated by the pressure differential is difficult to overcome and often may exceed the force capable of being generated by a backup piston, probe, or other extendible component of the tool. The use of pistons to dislodge a stuck tool is also unsatisfactory because the exact portion of the tool that is in contact with the wall is typically not known, and therefore several pistons spaced circumferentially about the tool must be provided in order to insure that a pushing force can be generated in the appropriate direction. Such pistons can be damaged during tool release operations, preventing their retraction and exacerbating the sticking problem. Other known methods for disengaging downhole tools, such as fishing, cable pulling, and tool pushing by tubing, are overly difficult and time consuming.

In some prior art teachings, a wall-disengaging assembly is carried by a downhole tool, such as the drilling tool 10 of FIG. 1 or the wireline tool 10′ of FIG. 2. FIG. 1 depicts a downhole drilling tool 10 deployed from a rig 5 and advanced into the earth to form a wellbore 14. The wellbore penetrates a subterranean formation F containing a formation fluid 21. The downhole drilling tool is suspended from the drilling rig by one or more drill collars 11 that form a drill string 28. “Mud” is pumped through the drill string 28 and out bit 30 of the drilling tool 10. The mud is pumped back up through the wellbore and to the surface for filtering and recirculation. As the mud passes through the wellbore, it forms a mud layer or mudcake 15 along the wellbore wall 17. A portion of the mud may infiltrate the formation to form an invaded zone 25 of the formation F.

The downhole drilling tool 10 may be removed from the wellbore and a wireline tool 10′ (FIG. 2) may be lowered into the wellbore via a wireline cable 18. The downhole tool 10′ is deployable into wellbore 14 and suspended therein with a conventional wireline 18, or conductor or conventional tubing or coiled tubing, below the rig 5. The illustrated tool 10′ is provided with various modules and/or components 12 including, but not limited to, a probe 26′ for establishing fluid communication with the formation F and drawing the fluid 21 into the downhole tool as shown by the arrows. Backup pistons 8 may be provided to further thrust the downhole tool 10′ against the wellbore wall 17 and assist the probe in engaging the wellbore wall 17.

However, none of these tools can be used for smearing a thief zone in a hydrocarbon well, or can strengthen the wellbore to prevent downhole losses, prevent pipe sticking, and improve the hole cleaning process.

SUMMARY

Accordingly, one example embodiment of the present disclosure is a downhole tool for use within a wellbore extending into an underground formation. The tool includes a wellbore wall disengaging assembly having a tubular string defining a longitudinal axis, and a plurality of longitudinal blades forming a retractable sleeve around the tubular string, the retractable sleeve having a substantially contiguous inner profile in a closed position, and wherein the retractable sleeve is actuated based on an internal pressure in the tubular string proximate to the downhole tool. In one example embodiment, the retractable sleeve may be mounted in coaxial relation to the tubular string. In one example embodiment, the plurality of longitudinal blades of the retractable sleeve expand to a position with an increased internal diameter when the retractable sleeve is in an open position.

In one example embodiment, the retractable sleeve prevents a flow of a fluid in a lateral direction into the wellbore wall while in an open position, and permits the flow of the fluid in the lateral direction through at least one port in the closed position. In one example embodiment, the retractable sleeve is configured to translate the longitudinal axis of the tubular string away from the wellbore wall in response to rotation of the retractable sleeve relative to the tubular string. The assembly may further include a sensor for sensing pressure on the tubular string, and an actuator for receiving a pressure signal from the sensor and actuating the retractable sleeve. The sensor may be part of a cycling pressure mechanism. The actuator may be configured to move the plurality of longitudinal blades from the closed position to an open position and vice versa. The actuation may be aerodynamic or hydrodynamic in nature. In one example embodiment, the outer surface of the longitudinal blades comprise a smooth or grooved configuration. The tool may be used for smearing a thief zone in a hydrocarbon well, and strengthening the wellbore to prevent downhole losses, pipe sticking, and improving the hole cleaning process.

Another example embodiment is a method of disengaging a downhole tool from a wall of a wellbore extending into an underground formation. The method includes lowering a wellbore wall disengaging assembly, the assembly comprising a tubular string defining a longitudinal axis, and a plurality of longitudinal blades forming a retractable sleeve around the tubular string, the retractable sleeve having a substantially contiguous inner profile in a closed position, and actuating the retractable sleeve based on an internal pressure in the tubular string proximate to the downhole tool. The actuation may be configured to move the plurality of longitudinal blades from the closed position to an open position. In one example embodiment, the plurality of longitudinal blades of the retractable sleeve expand to a position with an increased internal diameter when the retractable sleeve is in an open position. The method may also include preventing a flow of a fluid in a lateral direction into the wellbore wall while in an open position; and permitting the flow of the fluid in the lateral direction through at least one port in the closed position. The method may also include translating the longitudinal axis of the tubular string away from the wellbore wall in response to rotation of the retractable sleeve relative to the tubular string.

In one example embodiment, the wellbore wall disengaging assembly may include a sensor for sensing pressure on the tubular string, and an actuator for receiving a pressure signal from the sensor and actuating the retractable sleeve. The actuation may be aerodynamic or hydrodynamic in nature. The method may also include smearing a thief zone in the hydrocarbon well, and strengthening the wellbore to prevent downhole losses, pipe sticking, and improving the hole cleaning process.

Another example embodiment is a downhole tool for use within a wellbore extending into an underground formation including a wellbore wall disengaging assembly having a tubular string defining a longitudinal axis, and a plurality of longitudinal blades forming a retractable sleeve around the tubular string. The retractable sleeve may have a substantially contiguous inner profile in a first position, and the plurality of longitudinal blades of the retractable sleeve expand to a position with an increased internal diameter when the retractable sleeve is in a second position.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the features, advantages and objects of the invention, as well as others which may become apparent, are attained and can be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiment thereof which is illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the drawings illustrate only example embodiments of the invention and is therefore not to be considered limiting of its scope as the invention may admit to other equally effective embodiments.

FIG. 1 is a schematic view of a downhole tool with unsticking apparatus according to the teachings of prior art.

FIG. 2 is a schematic view of a downhole tool with unsticking apparatus according to the teachings of prior art.

FIG. 3 is a schematic view of a downhole tool, according to one or more example embodiments of the disclosure.

FIGS. 4A-C illustrate cross-sectional views of a downhole tool, according to one or more example embodiments of the disclosure.

DETAILED DESCRIPTION

The methods and systems of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The methods and systems of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout.

Turning now to the figures, FIG. 3 is a schematic, cross-sectional, view of a downhole tool or smart tool 100 for use within a wellbore 110 extending into an underground formation, according to one or more example embodiments of the present disclosure. The tool 100 has a wellbore wall disengaging assembly 108 including a tubular string 102 defining a longitudinal axis, and a plurality of longitudinal blades 104 forming a retractable sleeve 114 around the tubular string 102. The blades 104 may be attached to the string 102 using mechanical means 112, which may be aerodynamic or hydrodynamic in nature. Although only one blade 104 is illustrated in FIG. 3, the retractable sleeve may include two or more blades 104, as illustrated in FIGS. 4A-C. The assembly 108 may further include one or more sensors 106 for sensing pressure on the tubular string, and one or more actuators 112 for receiving a pressure signal from the sensor and actuating the retractable sleeve 114. The sensors 106 may be part of a cycling pressure mechanism, for example. The actuator 112 may be configured to move the plurality of longitudinal blades 104 from the closed position to an open position, and vice versa. The actuation may be aerodynamic or hydrodynamic in nature, as discussed above. In one example embodiment, the outer surface of the longitudinal blades 104 may include a smooth, shaped, or grooved configuration. The tool 100 may be used for smearing a thief zone in a hydrocarbon well, and strengthening the wellbore to prevent downhole losses, pipe sticking, and improving the hole cleaning process.

FIGS. 4A-C illustrate cross-sectional views of a downhole tool 200, according to one or more example embodiments of the disclosure. The downhole tool 200 is the same as tool 100, except with three blades shown for illustration purposes only. As illustrated in FIG. 4A, the retractable sleeve 214 formed from blades 204 may have a substantially contiguous inner profile in a closed position. The retractable sleeve 214 is actuated based on an internal pressure in the tubular string 202 proximate to the downhole tool 200. In one example embodiment, the retractable sleeve 214 may be mounted in coaxial relation to the tubular string 202. In another example embodiment, the retractable sleeve 214 may be mounted in non-coaxial relation to the tubular string 202. As illustrated in FIGS. 4B and 4C, the plurality of longitudinal blades 204 of the retractable sleeve 214 expand to a position with an increased internal diameter when the retractable sleeve 214 is in an open position.

In one example embodiment, the retractable sleeve 214 prevents a flow of a fluid in a lateral direction into the wellbore wall while in an open position, as illustrated in FIG. 4C, and permits the flow of the fluid in the lateral direction through at least one port in the closed position, as illustrated in FIG. 4A. In one example embodiment, the retractable sleeve 214 is configured to translate the longitudinal axis of the tubular string away from the wellbore wall in response to rotation of the retractable sleeve 214 relative to the tubular string 202. This may be achieved using mechanical or electrical means known to one of ordinary skill in the oil and gas well drilling art.

Another example embodiment is a downhole tool or smart tool for use within a wellbore extending into an underground formation. The tool includes a wellbore wall disengaging assembly having a tubular string defining a longitudinal axis, and a plurality of longitudinal blades forming a retractable sleeve around the tubular string. The retractable sleeve may have a substantially contiguous inner profile in a first position, such as a closed position, and the plurality of longitudinal blades of the retractable sleeve can expand to a position with an increased internal diameter when the retractable sleeve is in a second position, such as an open position, for example.

Referring back to FIG. 3, another example embodiment is a method of disengaging a downhole tool or smart tool 100 from a wall of a wellbore 110 extending into an underground formation. The method includes lowering a wellbore wall disengaging assembly 108 into the wellbore 110. The assembly 108 may include a tubular string 102 defining a longitudinal axis, and a plurality of longitudinal blades 104 forming a retractable sleeve 114 around the tubular string 102. The retractable sleeve 114 may have a substantially contiguous inner profile in a closed position when the plurality of blades are abutting each other. The method includes actuating the retractable sleeve 114 based on an internal pressure in the tubular string 102 proximate to the downhole tool. The actuation may be configured to move the plurality of longitudinal blades 104 from the closed position to an open position. In one example embodiment, the plurality of longitudinal blades 104 of the retractable sleeve expand to a position with an increased internal diameter when the retractable sleeve 114 is in an open position. The tool 100 may prevent flow of a fluid in a lateral direction into the wellbore wall 110 while in an open position, and may permit the flow of the fluid in the lateral direction through at least one port in a closed position. The method may also include translating the longitudinal axis of the tubular string 102 away from the wellbore wall 110 in response to rotation of the retractable sleeve 114 relative to the tubular string 102. This may be achieved using mechanical or electrical means known to one of ordinary skill in the oil and gas well drilling art.

In one example embodiment, the wellbore wall disengaging assembly 108 may include a sensor assembly 106 for sensing pressure on the tubular string 102, and an actuator 112 for receiving a pressure signal from the sensor 106 and actuating the retractable sleeve 114. The actuation may be aerodynamic or hydrodynamic in nature. The step of actuating the retractable sleeve 114 may enable smearing a thief zone in the hydrocarbon well, and strengthening the wellbore to prevent downhole losses, pipe sticking, and improving the hole cleaning process. Although certain example embodiments disclosed herein refer to the term “actuate” or “actuating” or “actuation,” these terms are synonymous with the terms “activate” or “activating” or “activation,” respectively. Similarly, while translating the tool from a closed position to at least a partially open position may constitute actuation or activation, translating the tool from an at least partially open position to a closed position may constitute “deactivation.”

The primary objective of the example embodiments disclosed herein is to support drilling efforts, to minimize drilling costs, and to improve operation cost effectiveness safely, in the most efficient way. This includes the multi-size interchangeable smart tool 100, 200 to be activated and deactivated as needed for purpose of smearing the thief zones, and enhancing the wellbore strengthening to prevent downhole losses, pipe sticking, and improve the hole cleaning process.

The smart tool or downhole tool 100, 200 can be run in close position and be ready for activation to the recommended size to prevent the losses from happening. Additionally, it can be used in conjunction with wellbore strengthening and lost circulation materials to enhance the efficiency of the system (mud and tool) utilizing a mechanical method and drilling fluids blends. The smart tool or downhole tool 100, 200 can be activated and deactivated on demand during tripping or whenever it may be required.

As oil and gas operators globally strive to enhance drilling efficiency and reduce the cost and non-productive time in the rig, a new way of enhancing the performance of drilling operations is to provide this smart interchangeable design system suitable for smearing the hole. This smart tool has a well-defined characteristics in its design which is retractable for more robust drilling modes. This smart design will allow the operator to control the degree of expansion of the tool to fit the hole size shape and conditions from inside to prevent hole collapse and at the same time can be used as wellbore strengthening mechanical tool to prevent the pipe from getting stuck. The smart tool or downhole tool 100, 200 described in the above example embodiments can be controlled thru mud pulses from the rig floor or at office for safety purpose.

The other advantage is that the smart tool or downhole tool 100, 200 fits different drill pipe standard connections. The smart tool can be used if complete loss of circulation is expected while drilling in surface holes, intermediate, or production hole sections. More complex wells can be drilled using the smart tool to sustain the drilling conditions and serve the purpose on demand since it is durable enough for unexpected events during drilling e.g. fishing, tight holes, etc.

The smart tool or downhole tool 100, 200 of the above example embodiments has hydrodynamics built-in design to activate and prevent differential sticking and could be used as smart mechanical device to free differential sticking and allow to open hole back to original hole size thus eliminating mechanical sticking during drilling. Additionally, the smart tool is designed to be used in all applications in vertical, deviated, and horizontal sections. Importantly, one of the main objective of this tool is that it can enhance the hole cleaning capabilities to allow better cuttings agitation across deviated or horizontal sections in which it can eliminate pipe sticking.

Additionally, the smart tool or downhole tool 100, 200 can provide an optimized smart solution along with drilling fluids to avoid the most chronic challenging hole problems encountered while drilling e.g. pipe sticking, loss circulation, and hole cleaning. This smart tool can also fill the gap in current technologies between fluids and downhole tools. Additional smarter tools such as real-time data acquisition can be linked to extend the functional and effectiveness of the smart tool to cover full range of functionality in order to enhance the drilling performance and reduce the cost.

The Specification, which includes the Summary, Brief Description of the Drawings and the Detailed Description, and the appended Claims refer to particular features (including process or method steps) of the disclosure. Those of skill in the art understand that the invention includes all possible combinations and uses of particular features described in the Specification. Those of skill in the art understand that the disclosure is not limited to or by the description of embodiments given in the Specification.

Those of skill in the art also understand that the terminology used for describing particular embodiments does not limit the scope or breadth of the disclosure. In interpreting the Specification and appended Claims, all terms should be interpreted in the broadest possible manner consistent with the context of each term. All technical and scientific terms used in the Specification and appended Claims have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs unless defined otherwise.

As used in the Specification and appended Claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly indicates otherwise. The verb “comprises” and its conjugated forms should be interpreted as referring to elements, components or steps in a non-exclusive manner. The referenced elements, components or steps may be present, utilized or combined with other elements, components or steps not expressly referenced.

Conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain implementations could include, while other implementations do not include, certain features, elements, and/or operations. Thus, such conditional language generally is not intended to imply that features, elements, and/or operations are in any way required for one or more implementations or that one or more implementations necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and/or operations are included or are to be performed in any particular implementation.

The systems and methods described herein, therefore, are well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While example embodiments of the system and method have been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications may readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the system and method disclosed herein and the scope of the appended claims. 

1. A downhole tool for use within a wellbore extending into an underground formation, comprising: a wellbore wall disengaging assembly, comprising: a tubular string defining a longitudinal axis; and a plurality of longitudinal blades forming a retractable sleeve around the tubular string, the retractable sleeve having a substantially contiguous inner profile in a closed position, and wherein the retractable sleeve is actuated based on an internal pressure in the tubular string proximate to the downhole tool.
 2. The downhole tool of claim 1, wherein the retractable sleeve is mounted in coaxial relation to the tubular string.
 3. The downhole tool of claim 1, wherein the plurality of longitudinal blades of the retractable sleeve expand to a position with an increased internal diameter when the retractable sleeve is in an open position.
 4. The downhole tool of claim 1, wherein the retractable sleeve prevents a flow of a fluid in a lateral direction into the wellbore wall while in an open position, and permits the flow of the fluid in the lateral direction through at least one port in the closed position.
 5. The downhole tool of claim 1, wherein the retractable sleeve is configured to translate the longitudinal axis of the tubular string away from the wellbore wall in response to rotation of the retractable sleeve relative to the tubular string.
 6. The downhole tool of claim 1, wherein the wellbore wall disengaging assembly further comprises: a sensor for sensing pressure on the tubular string, and an actuator for receiving a pressure signal from the sensor and actuating the retractable sleeve.
 7. The downhole tool of claim 6, wherein the sensor is part of a cycling pressure mechanism.
 8. The downhole tool of claim 6, wherein the actuator is configured to move the plurality of longitudinal blades from the closed position to an open position and vice versa.
 9. The downhole tool of claim 8, wherein the actuation is aerodynamic or hydrodynamic in nature.
 10. The downhole tool of claim 1, wherein the outer surface of the longitudinal blades comprise a smooth or grooved configuration.
 11. The downhole tool of claim 1, wherein the tool is used for smearing a thief zone in a hydrocarbon well, and strengthening the wellbore to prevent downhole losses, pipe sticking, and improving the hole cleaning process.
 12. A method of disengaging a downhole tool from a wall of a wellbore extending into an underground formation, comprising: lowering a wellbore wall disengaging assembly, the assembly comprising a tubular string defining a longitudinal axis, and a plurality of longitudinal blades forming a retractable sleeve around the tubular string, the retractable sleeve having a substantially contiguous inner profile in a closed position; and actuating the retractable sleeve based on an internal pressure in the tubular string proximate to the downhole tool.
 13. The method of claim 12, wherein the actuation is configured to move the plurality of longitudinal blades from the closed position to an open position.
 14. The method of claim 13, wherein the plurality of longitudinal blades of the retractable sleeve expand to a position with an increased internal diameter when the retractable sleeve is in an open position.
 15. The method of claim 14, further comprising: preventing a flow of a fluid in a lateral direction into the wellbore wall while in an open position; and permitting the flow of the fluid in the lateral direction through at least one port in the closed position.
 16. The method of claim 12, further comprising: translating the longitudinal axis of the tubular string away from the wellbore wall in response to rotation of the retractable sleeve relative to the tubular string.
 17. The method of claim 12, wherein the wellbore wall disengaging assembly further comprises: a sensor for sensing pressure on the tubular string, and an actuator for receiving a pressure signal from the sensor and actuating the retractable sleeve.
 18. The method of claim 12, wherein the actuation is aerodynamic or hydrodynamic in nature.
 19. The method of claim 12, further comprising: smearing a thief zone in the hydrocarbon well; and strengthening the wellbore to prevent downhole losses, pipe sticking, and improving the hole cleaning process.
 20. A downhole tool for use within a wellbore extending into an underground formation, comprising: a wellbore wall disengaging assembly, comprising: a tubular string defining a longitudinal axis; and a plurality of longitudinal blades forming a retractable sleeve around the tubular string, the retractable sleeve having a substantially contiguous inner profile in a first position, and wherein the plurality of longitudinal blades of the retractable sleeve expand to a position with an increased internal diameter when the retractable sleeve is in a second position. 